Process of manufacturing diazodinitbophenol



Patented July 3, 1923.

WILLIAM H. DEHN, OF SEATTLE, WASHINGTON.

PROCESS OF MANUFACTURING DIAZODINITROPHENOL.

Ho Drawing.

To all whom it may concern:

Be it known that I, WILLIAM M. D'EHN, a'

, citizen of the United States, and a resident of Seattle, county ofKing, and State of Washington, have invented certain new and usefulImprovements in Processes of Manufacturing Diazodinitrophenol, of whichthe following is a specification.

The invention relates to the manufacture of diazodinitrophenol(4.6-dinitro-2-diazophenol).

of with free I cal absence 0 Inthe manufacture of diazodinitrophenol,nitrous acid (N 0,) has hitherto been passed as a gas, either intoalcohol solutions of picramic acid or into ether solutions of the same,or into aqueous nitric acid solutions of the same. The alcohol methodhas hitherto yielded the best results. the aqueous nitric acid methodyielded bad admixtures with picric acid and dinitroglucinol, it wasabandoned by Griess and others for the alcohol method.

According to the present invention, ammonium picramate instead of freepicramic acid is em loyed and the uses of gaseous nitrous aci andorganic solvents are dispensed with. The ammonium picramate is reactedupon by substantially anhydrous nitric acid, in the presence of areducing agent, such as the alcohols, the sugars an the like. In thisway oxidation of ammonium picramate or of free picramic acid to picricacid is avoided, and substantially quantitative yields ofdiazodinitrophenol are obtained.

It is believed that the enhanced yields can be accounted for by theformulas:

" 'ONH4 m1, No,- 0| SHNO;) k0: BHNO:

wherein it will be observed that the hydrogen atoms attached to the twonitrogen atoms are oxidized so as to yield the diazodinitrophenoldirectly. The nitrous acid in statu nascendi then further promotes theformation of the same compound. The high yields with ammonium picramate,instead icrarnic acid, and the practiammonium nitrate in the filtratesindicate the above course of reactions.

Fumin ployed 0 about 1.5 specific gravity. The

Because nitric acid is preferably e1 n Application filed December 9,1919. Serial No. 848,592.

use of such acid presents numerous features of advantage, including highconcentration and oxidizing ower, good solvent properties, limitedydrolyzing influence and ready capacity to yield nascent nitrous acid,An excess of the acid is desirable to reduce hazards of combustion andexplosion, but this excess is kept low, and is ultimately removed sothat the precipitation of diazo-- dinitrophenol by water may be ascomplete as possible. always added to the acid that an excess of nitricacid may always be present.

Without a reducing agent for the nitric 'acid the diazodinitrophenol isinvariably contaminated with picric acid, because 0 the chenncalreaction:

the alcohol here used can be substituted by carbohydrates, etc.-

A floating layer of high boiling parafline hydrocarbon oil is emplo ed,such as kerosene'or low melting para ne wax. It is de-. sirably freefrom aromatic compounds which would interfere with the reaction andresult in production of impure diazodinitrophenol. The layer-of oil isnecessary to reduce spontaneous surface combustion of materials and,during the latter stages of the process, to eliminate hazard ofexplosion of the entire charge. Furthermore, the oily layer assists inthe retention of the oxides of nitrogen. This rotection from explosionby an oily layer in the manufacture of explosives, as far as I am aware,has not been employed hitherto.

The following example is given for the purpose of illustrating one wayof carrying out my invention:

Fuming nitric acid of about 1.5 specific gravity is placed in aconverter and is covered with neutral oil, preferably parafiine oil,such as kerosene, low melting parafiine wax, or the like, substantiallyfree from The ammonium picramate is aromatic compounds. Ammonium .picra--taining oxides of nitrogen results.

The quantities used (by weight) may be about as follows:

I Parts. Nitric acidof about 1.5 specific gravity 100 Parafiinehydrocarbons preferably more than 200' Ammonium picramate 40 Alcohol orcarbohydrate 10 Themixture may be permitted to stand or ma be heatedgradually up to about 100 until the evolution of gas ceases.

A brown-red lower layer, possibly containing yellow solid, and a clearjupper layer of parafiine oil are thus obtained. For obvious' reasons,the formation of solid diazodinitrophenol at this stage is to be avoidedand if a tendency toward production of solid diazodinitrophenol isnoted, evapora-' tion may be reduced or more nitric acid may be added inorder to avoid the formation of solid diazodinitrophenol- The materialis run into a separator and after standing for some time, the greaterpart of the parafline layer is run off to be used again for newcharges.The lower acid layer 'is run ofi as closely as practicable, and more orless'of an intermediate layer is left to be mingled with subsequentchanges from the converter. I

The nitric acid solution of diazodinitrophenol, drawn ofi' from thebottom of the separator, is run vertically in thin streams into stirredwater, at such a rate that no large masses of solid or of oil separate.By this treatment a bright yiell ow powdery sediment is obtained and,after standing, may be decanted or filtered, washed with Waterand storedin contact with water, or dried at temperatures not exceeding 100 C.

The yield thus obtained is over 90% of the theo As thediazodinitrophenol so pro- ,duce is'substantially pure, no furthertreatment is required, but, if desired, it may be gold-yel owrectangular 'of diazodinitrophenol are obtained.

recrystallized as by dissolvin in nitrobenzene at 100 and letting coo orby pouring warm acetone solutions or into of it into other soline andlettin stand, whereby akes or leaflets The color of the aqueous filtratemay be used as an indication of the success of the process, since dee.color is caused by picric acid, but diaz 'nitrophenol colors the wateronly slightly.

The aqueous filtrates may be evaporated .monium picramate,

to dryness and yield a mixture of diazodinitrophenol, picric acid,oxalic acid, 'etc., about equal to the remainder of the theoreticalyield. The usual modes of separation and purification may are includedwithin the scope of my claims may be resortedto, without departing frommy invention or sacrificing the advantages thereof.

I claim: 1. The phenol, wiich comprises reactin on ammonium picramatewith nitric aci substantially free from water in the presence of areducing agent for the nitric acid by adding the ammonium picramate tothe acid so as to maintain the acid in excess until the reaction iscomplete. 2. The process of making diazodinitro phenol, which comprisesreacting on ammomum picramate with fuming nitric acid in excess ofreactive requirements in the presence of a reducing agent for nitripacid.

3. The process of making diazodmitrophenol, which comprises reacting onainmonium picramate w th nitric acid slightly in excess of reactiverequirements of substantially 1.5 specific gravity in the presence of areducing agent for nitric acid.

4. The process-bf making diazodinitrophenol, which monium picramate withnitric acid of substantially the highest-concentration in. the presenceof alcohol as'a' reducing a cut for nitric acid, and covering thereacting materials with a layer of neutral oil to pre-f vent combustionand explosion.

5. The process of making diazodinitrophenol, which comprises reacting onammonium picramate with nitric acid in excess of reactive requirementsof substantially the highest concentration in the presence of alcohol asa reducing agent by adding the ammonium picramate slowly to the acid,and precipitating the reaction product in water.

6. The rocess of making diazodinitroich comprises reacting on* emwithnitric acid of about 1.5 specific gravity in the presence of a reducingagent for nitric acid, and covering phenol, w

the reagents with a layer of neutral oil,

separating the reaction product from the rocess of makingdiazodinitrocomprises reacting on am .oil, and precipitating thereaction product in water.

7. The rocess of making diazodinitrophenol, w ich comprises reacting onammonium picramate with nitric acid of substantially the highestconcentration in the presence of a reducing agent for nitric acid,covering the reagents with a layer of neutral hydrocarbon oil,separating the reaction product in liquid form from the oil, as bygravity separation, and entering such liquid reaction product into waterin a finely divided state, whereby diazodinitrophenol is precipitated insolid form.

8. The process of making diazodinitrophenol, which comprises reacting onammonium picramate with fuming nitric acid of substantially 1.5 specificgravity in the presence of alcohol as a reducing agent for nitric acid,protecting the reagents'with a top layer of neutral oil, separating thereaction product in li uid form from the oil, entering same in a nelydivided state into water, collecting the precipitated material andpurifying sameby crystallizing from solution.

9. The process of making diazodinitrophenol, which comprises the step ofreacton ammonium picramate with nitric acid slightly in excess ofreactive requirements in the presenceof material adapted to react with tnitrous acid by adding the ammonium picramate and said materialsimultaneously to the acid at a slow rate.

10. "The process of making diazodinitrophenol, which comprises reactingon elmmonium picramate with the reaction product of nitric" acid and areducing agent therefor consisting of alcohol, the nitric acid beingpresent slightly in excess of reactive requirements.

11. The process of making diazodimtrophenol, which consists in reactingwith an excess of nitric acid on a mixture of ammonium picramate and areducing agent for nitric acid, raising the mixture to approximately 100C. and maintaining said temperature whereby nitrous acid is produced,

e nitric acid to form nascent and the ammonium picramate therebyconverted into diazodinitrophenol without expelling an excess of nitricacid.

12. The process of making diazodinltrophenol, which consists in covering'a body of nitric acid of about 1.5 specific gravity with a layer ofneutral oil, and introducing simultaneously ammonium picramate and areducing agent for nitric acid into the acid through the oil layer, therate of addition and the temperature of the reagents being keptsufliciently low to avoid the copious evolution of redfumes. I 13. Inthe process of making diazodinitro: phenol from ammonium picramate, thestep which comprises introducing such material mixed with a reducingagent for nitric acid through a top layer of oil into a body of nitricacid of substantially 1.5 specific gravity.

14. The process of making diazodinitro- (phenol, which consists inentering ammonium picramate admixed with a reducing agent for nitricacid, into a body of nitric acid, through a' protective layerofparafiine oil, regulating the rate at which the material is added andcontrolling the temperature so that evolution of red fumes is re.- ducedto substantially the minimum.

. 15. Thejprocess of making diazodinitrophenol, which comprisesintroducing into a converter about 100 parts of fuming nitric acid ofsubstantially 1.5 specific ,gravity, covering same with at least 200parts of a vparafiine oil free from aromatic compounds, introducing intothe acid through the oil, a mixture of about 40 parts ammonium picramateand about '10 parts grain alcohol, while agitating and controlling thetemperature so thatcopious production of red fumes is avoided;separating the reactionmixture form and in a thin stream into water,whereby the diazodinitrophenol is precipitated in solid form. p

In testimony that I claim the foregoing,

- I hereto set my hand, this 17th day of November, 1919.

WILLIAM M. DEHN.

from the oil, and entering same in liquid 1

